They are very smart animals. That video shows how smart they are. Most people would think wild critters wouldn't want anything to do with a big snapping turtle.

  Instead that otter stayed out of snapping range, came in from the back and went under and flipped the snapper on his back and it was all over.

Reminded me of watching a mongoose kill a big cobra. The difference in intelligence from a reptile brain and a warm blooded mammal brain.